resolve 1.6 pullup tickets #12 and #20, submitted by thorpej.
This change pulls up revisions 1.43 and 1.44
Original messages:
> Add a scanf format attribute to __svfscanf().
and
> Parameterize the vfscanf macro's arguments. Without them, 3rd party
> software can become greatly confused.
>
> This fixes 4 GCC 3.2 testsuite failures.
>
> This is a stop-gap measure which can be easily applied to the 1.6
> release branch. A different fix for the trunk is forthcoming.